Animals infections

Infection of animals Infection of man Method of virus infection... 

Animal infectivity methods Some viruses do not cause recognizable effects in cell cultures but cause death in the whole animal. In such cases, quantification can only be done by some sort of titration in infected animals. The general procedure is to carry out a serial dilution of the unknown sample, generally at ten-fold dilutions, and samples of each dilution are injected into numbers of sensitive animals. After a suitable incubation period, the fraction of dead and live animals at each dilution is tabulated and an end point dilution is calculated. This is the dilution at which, for example, half of the injected animals die. Although such serial dilution methods are much more cumbersome and much less accurate than cell culture methods, they may be essential for the study of certain types of viruses. 

Both male and female tsetse live solely on vertebrate blood, and the various species that carry sleeping sickness typically feed not only on humans but also on both domestic and wild animals. Infected flies pass on trypanosomes whenever they take a blood meal, so that the parasites not only move between flies and humans, but also infect a number of other hosts. Infected domestic animals develop nagana, but wild animals may show no sign of illness. They serve instead as healthy animal reservoirs of trypanosomes, permitting tsetse flies to pick up the parasites at any time without necessarily feeding on infected humans or domestic animals. For this reason and also because available drug therapies have proved no more practical here than for leishmaniasis, control of trypanosomiasis has long emphasized eradication of tsetse flies. 

Fig. 11. Megacaryocytes of the spleen (a) animals infected with influenza virus (b) animals infected with influenza virus that were administered MFPC Grinization . Hematoxilin-eosin staining, magnification x 400.

With the exception of leurosine, all three alkaloids significantly prolonged the life of animals infected with the PI534 leukemic cell line. This effect was observed even when treatment was delayed until the animals were nearly moribund. However, and perhaps most interestingly, it was observed that cured animals were resistant to additional challenges with this tumor line (i). Sadly, these results could not be extrapolated to clinical situations. 

The advisability of using certain antibiotics, particularly penicillin and tetracycline, in animal feeds has been questioned because of their use in human medicine. Any use of an antibiotic that is prescribed for humans presents some risks to human health, whether the use is for humans, animals or for other purposes but. the uses also have benefits. Otherwise, they would not persist. Antibiotics are used in animal feeds to increase animal weight, increase efficiency of feed utilization, increase reproductive efficiency and decrease morbidity and mortality. These benefits to animals and animal producers are reflected in decreases in food costs to humans. There are also benefits to human health from use of antibiotics in food animals. By reducing the incidence of animal health problems, use of antibiotics in food animals reduce the transference of animal infections to humans. The contention that the effectiveness of penicillin and tetracycline for use in human medicine is rapidly diminishing as a result of the proliferation of resistant bacteria caused by subtherapeutic use of antibiotics in animal production is not supported by experimental data. Rather, the evidence suggests that a fairly stable level of resistance of the intestinal bacteria in humans has long since been established to penicillin and tetracycline as it has been in animals. 

Giardia lamblia 7 days Diarrhea which can last 1-2 weeks Dose >1 cysts Sewage, manure, wild and domestic animals, infected food handlers and water... 

Baltz T, Baltz D, Giroud C, Crockett J. Cultivation in a semi-defined medium of animal infective forms of Trypanosoma brucei T. equiperdum, I evansi, T. rhodesiense and T. gambiense. EMBO J 1985 4 1273-1277. 

It should be noted that Sendai virus is extremely infectious for rodents and very difficult to eradicate from a rodent housing facility once established. Animals infected with Sendai should not be housed in the same facility as other rodents used for experimental purposes and personnel handling. Sendai should be restricted from entering any rodent housing facility. Appropriate precautions should also be taken when disposing of virus-contaminated material. 

In 1850, Pierre-Francoise OHve Rayer (Rayer, 1850) and Casimir-Joseph Davaine (Davaine, 1863) reported the presence of small filiform bodies in the blood of anthrax-infected sheep (Carter, 1988). By 1855, Franz Aloys Antoine PoUender confirmed this discovery and impheated their role in producing anthrax disease (PoUender, 1855). In 1858, Freidrich August Brauell noted the bodies to be absent from healthy animals or animals infected with diseases other than anthrax. Brauell also noted their inability to be transmitted from pregnant sheep to fetus (Brauell, 1857). 

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